Looper for linking and sewing machines for sewing both with single-thread and twin-thread chainstitch

ABSTRACT

A looper for linking and sewing machines is disclosed, in which an adjustable extension is provided, which is adapted to render the looper alternatively adapted to sewing with a single-thread chainstitch or with a twin-thread chainstitch, as desired by the machine operator, without disturbing the original adjustment of the looper.

United States Patent [56] References Cited UNITED STATES PATENTS [72] Inventor CesareL.Conti rispi 5, Milan, Italy Viale Francesco C 9008 5 911 Q "HQ 2 222 l 111 l 111 m mS m m M m m.mm m a n A a n .n m w t .wm m a .w.mmE m RKA G O 6O0 345 6 999 9 Ill l l// l 727 I 00 5 .1 246 6 696 2 48 00 J 8 222 9 8 76 999 M 111 M 1 1 E062 wil zyn mh n 8 9 e 1 7'MFhM 0. d mm Wmmm flafi AFPP 111.11.] 2523 224333 .l[l:l.l:l

Pat. 823,745

Primary Examiner-Richard J. Scanlan, Jr. Attorney-B. Edward Schlesinger [54] LOOPER FOR LINKING AND SEWING MACHINES FOR SEWING BOTH WITH SINGLE-THREAD AND TWIN-THREAD CHAINSTITCH 3 Claims, 4 Drawing Figs.

ABSTRACT: A looper for linking and sewing machines is disadj d, which is er alternatively adapted to sewing -thread chainstitch or w 112/218, 112/199 [51] Int. D05b 57/02 [50] 112/25, 199, 218

the original adjustment of the looper.

PATENTED FEBI'SIQYI I SHE 1 2 3,563,194

INVENTOR Cesare L can,

" I ATroRNEY 3.563194 v sum am 2 PATENT EU FEB] 6197i Y INVENTOR Cesare cont;

Z ZTTORNEY LOOPER FOR LINKING AND SEWING MACHINES FOR SEWING BOTH WITH SINGLE-THREAD AND TWIN- THREAD CHAINS'I'ITCII This invention relates to a looper. for linking machines and sewing machines, which is adapted to sew both with a singlethread and twin-thread chainstitch.

It is known that, in linking machines for hosiery and sewing machines in general, whenever it is desired to pass from singlethread chainstitch to twin-thread chainstitch, or vice versa, the looper should be replaced and the hole adjustment of the looper should be made again. These operations involve a considerable waste of time which has an influence on the machine output. t p

An object of the present invention is to provide a looper which is adapted to perform, as selected by the operator of a linking machine or another sewing machine, the sewing with single-thread chainstitch or the sewing with twin-thread chainstitch.

Another object of the present invention is to enable an operator of a linking machine or of any other sewing machine, to discontinue the sewing operation with a single thread chainstitch to pass, without any 'other intermediate step, directly to sewing with a twin-threadchainstitch, or vice versa, without modifying the adjustment of thelooper.

According to the invention,"a looper of the kind which is generally suited to sewing with a twin-thread chainstitch, and thus equipped with two passage holes'for either thread, one hole being arranged in the neighborhood of the tip of the looper an the other hole in the neighborhood of the connecting arc of the looper with it shank, is characterized in that it has, in a position which is slidably adjustable along it shank, an extension which is oriented parallel to the axis of the tip of the looper, said extension carrying, integrally and in 'a direction perpendicular to the axis of the looper tip, a cylindrical rod whose axis is the extension of the axis of a cylindrical hollow formed in the looper in the immediate neighborhood of the looper tip, so as to enable said cylindrical rod either to close said hollow in the looper tip, or to leave it open, at the machine operators choice. i

Other objects, features and advantages of the invention will become fully apparent from the detailed description, to be set forth hereinafter, of a preferred embodiment of the invention as depicted in the accompanying. drawings, which show said embodiment without involving any limitation of the present invention thereto.

In the drawings: v 1 7 FIG. I shows a portion of the point dial of a linking machine which is performing a twin-thread {chainstitch by using the looper according to the presentinvention;

FIG. 2 shows a closeup of the looper according to the invention and the two sewing threads are also shown;

FIG. 3 is a view similar to FIG. 2, but shows the machine while performing a single-thread chainstitch with the looper made accordingto this invention the cylindrical rod having been slipped into the cylindrical hollow adjacent to the looper tip;and

FIG. 4 is a closeupofFlGB. Having initially reference to FIGS." 2 and 4, which are closeups, it'will be readily noticedthat the looper has two holes, 2 and 3, formed in the neighborhood of the connecting arc between the needle tip and the shank, and in the immediate neighborhood of the tip, respectively. These two holes are intended, as is usual for loopers to be used for making a twin-thread chainstitch, in order to allow a passage for either thread; that is to say, in the case of the drawing, the thread 7. On the shank of the needle I is mounted, in a slidably adjustable manner by the agency of the setscrew 5, an extension 4, which extends in a direction perpendicular to the axis of the shank of the looper 1. To this extension, and parallel to the axis of the looper shank on the extension of the axis of a cylindrical groove or recess 12 formed in the neighborhood of the looper tip, is affixed a cylindrical rod 6 which can either be inserted into, or removed from, the groove 12, as

selected by the operator of the linkin machine. In the light of what has been described herembe ore, it can be readily noticed that, when the rod 6 is disengaged from the groove 12, the looper 1 can perform the twin-thread chainstitch in the conventional way. This can be readily seen in FIG. I, wherein the sewing looper 9 cooperating with the looper I, the point dial l0, and a few impaling pins '11, have been shown. Having now particular reference to FIG. 4,. it is immediately noticed that, when the rod 6 engages the hollow 12, the looper I becomes adapted to sewing with a single-thread chainstitch, in the case in point the thread 8. It can be seen in the drawings that, to pass from the configuration of FIGS. I and 2 (twinthread chainstitch) to the one of FIGS. 3 and 4 (single-thread chainstitch) it is sufficient to release the screw 5 and to cause the extension 4 to advance until the rod 6 locks the groove or recess 12 of the looper 1. Under such'conditions, the looper l is enabled to sew with a single-thread chainstitch, as can be seen in FIG. 3. To restore the looper to its position adapted to sewing with a twin-thread chainstitch, it is sufficient to reverse the sequence of the operations described above.

From the foregoing it is apparent that it is possible, in a linking machine having a looper made according to this invention, to convert from single-thread sewing to twin-thread sewing, and vice versa, at any time, without disturbing in any wise the adjustment of the looper. It is thus even possible to perform a portion of a work partly with 'a single-thread chainstitch and partly with a twin-thread chainstitch by employing the same looper, an operation which wasmanifestly impossible with the loopers made according to the prior art.

I claim:

1. A sewing machine looper of the kind adapted to sew with a twin-thread chainstitch and having two holes for allowing the passage therethrough of the thread, said looper having a shank portion and a tip portion, said tip portion being perpendicular to said shank portion, an extension slidably mounted on and perpendicular to said shank portion, said extension having positioning means thereon for selective placement thereof along said shank portion said extension carrying, integrally and in a direction perpendicular to the axis of said tip portion, a cylindrical rod, cylindrical hole for said rod formed in the immediate neighborhood of the end of said tip portion and coaxial with said rod, so as to enable said rod, at the choice of the operator of the linking machine, either to close said hole at the looper tip or leave the same open.

2. A looper according to claim 1, wherein said positioning means includes locking means whereby said extension can be locked in either of two positions, one position corresponding to the engagement of said cylindrical rod with said cylindrical hole, the other position corresponding to the disengagement of said rod from said cylindrical hole.

3. A looper according to claim 2, wherein the means for locking the extension in either of said two positions consists of a setscrew mounted at the end of said extension away from the end which carries said cylindrical rod. 

1. A sewing machine looper of the kind adapted to sew with a twin-thread chainstitch and having two holes for allowing the passage therethrough of the thread, said looper having a shank portion and a tip portion, said tip portion being perpendicular to said shank portion, an extension slidably mounted on and perpendicular to said shank portion, said extension having positioning means thereon for selective placement thereof along said shank portion, said extension carrying, integrally and in a direction perpendicular to the axis of said tip portion, a cylindrical rod, cylindrical hole for said rod formed in the immediate neighborhood of the end of said tip portion and coaxial with said rod, so as to enable said rod, at the choice of the operator of the linking machine, either to close said hole at the looper tip or leave the same open.
 2. A looper according to claim 1, wherein said positioning means includes locking means whereby said extension can be locked in either of two positions, one position corresponding to the engagement of said cylindrical rod with said cylindrical hole, the other position corresponding to the disengagement of said rod from said cylindrical hole.
 3. A looper according to claim 2, wherein the means for locking the extension in either of said two positions consists of a setscrew mounted at the End of said extension away from the end which carries said cylindrical rod. 